Ploidy variation in the group ofMyosotis palustris andM. laxa in the Czech Republic and Slovakia

In 74 natural populations of theMyosotis palustris andM. laxa groups from former Czechoslovakia three euploid and one aneuploid cytotypes were found that belong to the following species:M. nemorosa Besser, 2n=22,M. palustris (L.)Nath. em.Reichenb. inSturm, 2n=66,M. laxiflora Reichenb., 2n=66,M. radicans Opiz, 2n=66(64),M. brevisetacea (Schuster) Holub, 2n=66(64), andM. caespitosa C.F. Schultz, 2n=88. With the exception ofM. nemorosa, the chromosome numbers are published for the first time for the Czech Republic. The chromsome numbers, 2n=66, 2n=64 are found inM. brevisetacea, are new for the literature. The correlation between pollen size and ploidy level has been studied as well, and statistically significant differences were found between cytotypes belonging to different ploidy levels.     

Karyological studies in Jaborosa (Solanaceae)

Sixteen species of Jaborosa (Solanaceae), including eight endemic to Argentina, were studied karyologically. The numbers n  = 12 and/or 2n  = 24 were found in all species, the majority of the cases being new reports. Mitotic chromosomes were small- to medium-sized, the average length varying from 2.95 to 4.93 µm. All species had one to three chromosome pairs with satellites. The karyotypes, obtained for 13 species, were slightly asymmetrical: A ₁ ranged from 0.228 to 0.483, A ₂ ranged from 0.095 to 0.182, and Paszko's asymmetry index ranged from 0.84 to 3.47. In all species, metacentric chromosomes were the most common, followed by submetacentrics, but subtelocentrics were rare. Morphological similarities and sectional arrangements were not reflected in either a principal components analysis plot or asymmetry index plot, but the species could be singled out by their karyotype formulae and the different karyotype parameters taken. In Jaborosa , a notably diversified genus, exo-morphological evolution has taken place, together with evident chromosome rearrangements, whose disposition is different and not as clear as in related genera.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 467–478.     

Karyological and morphometric variation of the North African green frog Pelophylax saharicus (Anura) in northeastern Africa

Morphometric variation of Pelophylax saharicus was analysed using univariate and multivariate statistics, with both traditional and geometric morphometries, based on 148 specimens from four different geographical localities in Tunisia and Algeria. The results show the existence of three morphotypes in Tunisia and one in Algeria, and indicate a significant degree of variation in morphometric characters between regions. Specimens from the southernmost region have the smallest body size and the greatest morpho...     

Karyological differences among Tenebrionidae (Coleoptera)

Karyotypes obtained from spermatogonial metaphases of 20 tenebrionid species have been surveyed. The range of chromosome numbers is from 2n=16 to 2n=26, but only five species deviate from 2n=20, which is the modal and most primitive number of the family. Only the tribe Akidini shows a clear relationship between chromosome number (2n=16) and taxonomic group, while in the other species this relationship is not apparent. The mean total complement lengths in eleven species vary about twofold and the number of chromosome arms (NF) from 23 to 50. Some congeneric species ofTentyria, Hegeter andErodius displayed slight differences in the number of acrocentric chromosomes.Project number PB 87-0584-C02-01, Ministry of Education and Science, Spain     

Cytotaxonomische Untersuchungen in der Artengruppe desRanunculus alpestris (Ranunculaceae)

Morphological and cytological investigations as well as crossing experiments were carried out with the 5 species of theRanunculus alpestris group (R. alpestris L.,R. traunfellneri Hoppe,R. bilobus Bertol.,R. crenatus Waldst. etKit.,R. magellensis Ten.). A key to the species is presented; localities and distribution are given in addition to extensive diagnoses. Crossing experiments between the 5 taxa were successful (F₁-F₃ individuals, backcross types, tripeland quadrupelbastards); the morphology of the experimentally obtained F₁-hybrids was mostly intermediate. All 5 species as well as all hybrids have a chromosome number of 2n = 16; there is no statistically significant difference between the karyotypes of the 5 taxa. According to the results of the morphological investigations and the crossing experiments we can distinguish 2 subunits of very closely related species: a)R. alpestris, R. traunfellneri, R. bilobus; b)R. crenatus, R. magellensis. The speciation within the group ofRanunculus alpestris is discussed.

     

Electrophoretic variation of the apogamousDryopteris varia group (Dryopteridaceae)

A total of 35 electrophoretic variants were detected in four apogamous species of theDryopteris varia group: 14 variants inD. bissetiana triploids, 7 inD. sacrosancta triploids, 6 inD. varia triploids, 3 inD. pacifica triploids, and 5 in apogamous diploids. The variants differed from each other in various combinations of a few alleles which were common in some of the variants, suggesting recurrent origin.Dryopteris insularis var.insularis (2x) and var.chichisimensis (3x), other members of the group, were electrophoretically monomorphic, suggesting single origin. Banding patterns infer that triploids ofD. bissetiana andD. sacrosancta may have originated from hybrids whose parent is the sexualD. saxifraga, whereas this species was not involved in the origin of the other apogamous triploids and the apogamous diploids. The other parent was also discussed and we proposed a hypothesis that diploid offsprings fromD. pacifica triploids hybridized withD. saxifraga giving rise to triploids ofD. bissetiana andD. sacrosancta.     

Karyological analysis of the genus Canna (Cannaceae)

Somatic chromosome numbers and karyological features in 22 taxa of the genus Canna (Cannaceae) were investigated and are presented here for the first time. The chromosome numbers were primarily reported for C. bangii, C. indica var. sanctae-rosae and C. tulianensis. A triploid somatic chromosome number of 2n = 27 was found only in C. discolor, while the remaining taxa were diploids with 2n = 18. Chromosome numbers are considered to be remarkably stable within the Cannaceae. Canna shows a symmetric karyotype that consists mostly of median chromosomes, but with some subterminal or submedian chromosomes, and a karyotype homogenous in variation in chromosome length. The karyotype of some taxa of Canna, furthermore, is characterized by median chromosomes with a secondary constriction in the centromeric region. Cytotaxonomical characteristics of the family Cannaceae and the related groups in the Zingiberales are discussed.     

Chromosome differentiation in the Triturus alpestris complex (Amphibia: Caudata)

Several individuals from distinct populations of 7 subspecies included in the Triturus alpestris complex have been analysed to obtain characteristic C-banding patterns.The differences found among the populations as regards the amount, complexity and distribution of heterochromatin bands have been employed to test a pattern of chromosome evolution.Relevant similarities and dissimilarities of these populations are discussed in the light of the tentative evolutionary history inferred from a rooted tree.     

First Evidence of an Altitudinal Variation in the Brain Size of Triturus alpestris alpestris (Laur.) (Amphibia,Caudata, Salamandridae)

This study deals with geographical variations in brain-body weight relationships in the alpine newt, Triturus alpestris alpestris. According to the canonical axis, C.A., the mean allometry in this species is 0.473±0.03; an allometry value of 0.5 is considered to be characteristic of Caudata. No significant difference was observed between the four reduced major axes (R.M.A.) of lowland animal samples (mean value of the pooled samples, C.A. = 0.469±0.210). In contrast, between the mountain samples a significant difference exists, the R.M.A. in the sample from l'Alpe d'Huez (Isère, France) being 0.331±0.57 as compared to 0.72±0.18 in the sample from Durmitor (Montenegro, Yugoslavia). In spite of this difference, their encephalisation index (Ie) did not differ significantly, having on average a value of 118.18±8.5, against īe = 93.8±8.0 for lowland samples. A significant difference in encephalisation index between mountain and lowland alpine newts thus exists. This is probably the first observation in vertebrates of an encephalisation index increase with altitude. A biological hypothesis is proposed to explain this peculiar observation.     

Karyological features and cytotaxonomy of the tribe Vernonieae (Asteraceae)

Chromosome numbers are reported for 29 populations of 19 Vernonieae taxa collected mainly in the northeastern region of Brazil. Among them, data for five genera (Blanchetia, Rolandra, Pithecoseris, Stilpnopappus and Vanillosmopsis) are here reported for the first time, and the first chromosome counts are presented for 12 species. Chromosome numbers are quite diverse among and sometimes within genera, especially in the controversial and large subtribe Vernoniinae. The numbers varied from 2n = 18 to 2n = ~72. The main karyoevolutionary mechanism seems to be dysploidy, while polyploidy is probably associated with ancient hybridization processes generating most paleotetraploid genera. All studied species presented semi-reticulated interphase nuclei and proximal-early condensing behavior in prophase to prometaphase. In one species (Vernonia condensata with 2n = 40) fluorochrome staining with CMA/DAPI revealed five chromosome pairs bearing subterminal CMA⁺/DAPI^? heterochromatin, probably NOR-associated, revealing the existence of low amounts of satellite DNA. The role of these features in the evolution of the tribe is discussed, revealing some interesting aspects for understanding of the Vernonieae karyoevolution, especially regarding neotropical members.     

Karyological studies inCoris julis (Pisces,Labridae)

In the present investigation the diploid number 2n=48 (NF=58) has been determined for females, primary males, and secondary males ofCoris julis from the Gulf of Palermo. Differentiated sex chromosomes have not been observed in the population under study.     

Karyological notes onCentaurea sect.Acrocentron (Asteraceae)

The karyology ofCentaurea sect.Acrocentron is surveyed. 19 chromosome counts on 8 species are reported; those onC. acaulis, C. crocata, C. galianoi, C. pubescens, andC. malinvaldiana are new. The basic chromosome numbers of the section are x = 11 and x = 10. Karyological arguments have been used to show that evolution was from x = 11 to x = 10. This is supported by biogeographical data. Two main centres of diversification of sect.Acrocentron were studied from that point of view: the East and the Southwest Mediterranean region.     

濒危植物杜鹃红山茶的细胞学研究

报道了杜鹃红山茶(Camellia azalea)的细胞学资料。其间期核为球形前染色体型,有丝分裂前期染色体为中间型。核型公式为2n=2x=30=28m(1SAT) 2sm,核型类型属于Stebbins的1B型。第3、4、9、10、11、12条染色体的长臂上具有次缢痕,第15条染色体的短臂上具随体。细胞学证据支持杜鹃红山茶在山茶组中较为原始的推断,并为人工杂交育种时亲本的选择提出了一些建议。     

Karyological studies in Sonchus section Muritimi (Asteraceae) from the Iberian Peninsula

MEJÍAS, J. A. & VALDÉS, B., 1988. Karyologiepl studies in Sonchus section Madtimi (Asteraceae) from the Iberian Peninmula. Karyological data support the distinction of S. aquatilis Pourret and S. maritimus L. at the specific level. Karyological data and hybridization experiments support the idea that S. × novocaslcllanus Cirujano has been produced by the hybridization of S. crassifolius Pourret ex Willd. and S. maritimus L.     

Karyological Study on the Endangered Species Camellia azalea (Theaceae)

The chromosome number and karyotype of Camellia azalea were reported here for the first time . The species showed in somatic cells the round prochromosome type of the interphase nuclei and the interstitial type of the prophase chromosomes. It was a diploid , and the karyotype could be formulated as 2n = 2x = 30 = 28m (1SAT ) + 2sm, belonging to Stebbins’1B type. The third, fourth, ninth, tenth, eleventh and twelfth chromosomes had secondary constriction respectively, and one satellite had been found on the fifteenth chromosome. The cytological results supported the suggestion that C. azalea was primitive species in Sect . Camellia of the genus Camellia. A clue on selecting parents was also proposed due to the chromosome numbers and the position in Sect. Camellia.     

Taxonomy, variation, and relationships in the Hordeum parodii group (Poaceae)

The Hordeum parodii group contains three species, viz. H. parodii Covas (6x), H. tetraploidum Covas (4x), and H. fuegianum Bothmer, Jacobsen, et Jørgensen, sp. nov. (4x). The former two species mainly occur in C and S Argentina, while H. fuegianum is native to Tierra del Fuego. All three species are probably of alloploid origin. Morphological, isoenzyme variation and cytogenetic data are presented.